Micro-fluid jetting devices are suitable for a wide variety of applications including, but not limited to, hand-held ink jet printers, ink jet highlighters, and ink jet air brushes. One of the challenges to providing such micro-fluid jetting devices on a large scale is to provide a manufacturing process that enables high yields of high quality jetting devices. Another challenge is to provide fluid jetting devices, such as handheld painting and printing devices that are capable of precisely reproducing any color at any time without color anomalies, which may include color halos.
The use of handheld ink jet jetting devices for applying single colors to an object such as paper is a relatively simple operation. However, providing a mixture of color inks to an object using a micro-fluid jetting device presents significantly more challenges. For example, conventional handheld ink jet printing devices for printing multiple colors have a substantially linear nozzle arrangement as shown in FIG. 1. Nozzle holes 2 for cyan, 3 for magenta and 4 for yellow are illustrated. When the printhead having the foregoing substantially linear nozzle arrangement is used to produce a single solid color that is a mixture of two or more ink colors, unwanted color areas (hereafter referred to as “halos”) are deposited on the substrate as the printing device is moved. For example, when a conventional handheld ink jet printing device is moved in a perfectly linear direction, indicated by arrow 5, across a substrate to provide a composite black bar 6, unwanted cyan 7 and purple 8 halos appear on one side of the black bar 6 and unwanted orange 9 and yellow 11 halos appear on an opposite side of the black bar 6 along the linear direction the ink jet printing device is being moved, if the speed of movement is not perfectly linked to the timing of ink ejection. Additional halos may be formed if the printhead does not move in a perfectly linear direction. In order to produce the black bar 6, the printhead must be moved substantially in the direction indicated by arrow 5. If the printhead is moved perpendicular to the direction indicated by arrow 5, composite colors cannot be printed because nozzle holes 2 for cyan, 3 for magenta, and 4 for yellow do not pass over the same point on the media. Accordingly, there is a need for improved handheld micro-fluid jetting devices that provide more uniform jetting of fluids when moved in a linear direction across a media.
With regard to the foregoing and other objects and advantages exemplary embodiments of the disclosure provide a micro-fluid jetting device and a method of ejecting fluid mixtures onto a substrate. The micro-fluid jetting device includes a housing containing a logic circuit and fluid reservoirs for at least two different fluids. A micro-fluid ejection head is attached to a first end of the housing. The ejection head is in electrical communication with the logic circuit and the fluid reservoirs. At least two channel members are provided for directing fluid from the reservoirs to a plurality of fluid ejection nozzles in a nozzle plate member. The ejection nozzles for each of the at least two different fluids are arranged in the nozzle plate member so that adjacent ejection nozzles are in flow communication with different fluids. A power source in electrical connection with the micro-fluid ejection head is provided in the housing for activating the micro-fluid ejection head for jetting the fluids therefrom.
In another embodiment, the disclosure provides a method for jetting different fluids to provide a mixture of different fluids deposited onto a substrate. The method includes providing a housing containing a logic circuit, fluid reservoirs for at least two different fluids, and a micro-fluid ejection head attached to a first end of the housing. The ejection head is in electrical communication with the logic circuit and the fluid reservoirs. At least two channel members are provided in the ejection head for directing fluid from the reservoirs to a plurality of fluid ejection nozzles in a nozzle plate member. The ejection nozzles for each of the at least two different fluids are arranged in the nozzle plate member so that adjacent ejection nozzles are in flow communication with different fluids. A power source in electrical connection with the micro-fluid ejection head is provided in the housing for activating the micro-fluid ejection head for jetting the fluids therefrom. Upon activation of the micro-fluid ejection head a mixture of fluids is ejected onto the substrate.
An advantage of the exemplary embodiments described herein is that an essentially uniform mixture of fluids may be ejected onto a substrate regardless of the direction the printhead is being moved without causing the halo effect provided by conventional handheld fluid ejection devices.